The colds and flu are viral mantra

di11on

Hi folks,

I have a quick question which I wonder can someone from the medical profession shed some light on...

We hear time and time again that colds and flu are viral and there is no point taking antibiotics to treat them. In fact taking antibiotics unnecessarily can do harm in the long run because it can lead to resistant strains of bacteria.

However, in practice, I never get a cold or flu without the mucus turning green eventually. Doesn't this mean that there is a bacterial infection present at this point? My theory is that when you have a cold or flu, you are "at" your nose more what with sneezing and tissues and the whole lot. So with this increased contact, you get yourself a bacterial infection also. Or, perhaps the virus lowers your immune system enough to allow bacteria that were already there to get an increased foothold.

So I guess my point is this... a bacterial infection often seems to go hand in hand with cold or flu. So are vulnerable people not correct in wanting an antibiotic, even if it's just prophylactic?

challengemaster

di11on wrote: »

However, in practice, I never get a cold or flu without the mucus turning green eventually. Doesn't this mean that there is a bacterial infection present at this point?

Nope.

http://www.nhs.uk/Livewell/coldsandflu/Pages/Fivefactsaboutcolds.aspx

Yellow mucus is caused by white blood cells
When your immune system is fighting a cold virus, one of the first symptoms is clear, runny mucus from the nose. As the cold develops, mucus usually becomes thicker and yellow, then green. White blood cells cause this change in colour and texture as they flood to the nasal area and increase in number as the cold progresses.
"Many people think that yellow or green mucus is caused by bacteria, but this isn't the case," says Professor Eccles. "It's because there are billions of white blood cells in the mucus."

Or, perhaps the virus lowers your immune system enough to allow bacteria that were already there to get an increased foothold.

Your understanding of the immune system is seriously flawed. Viruses (excluding the likes of HIV) do not lower your immune system. Viruses take over your bodies own cells and use the cells "organs" to produce new viruses. These then get released, and the same thing happens again.

This article from the British Society of Immunology explains the whole process on how your immune system fights viruses very well

So are vulnerable people not correct in wanting an antibiotic, even if it's just prophylactic?

No.

Dingle_berry

Just to add to what Challenemaster said:
Antibiotics work against your natural/commensal/'good' bacteria too. When they are reduced the ecological niche that they occupied is left open to the next bacteria that comes along (which could be pathogenic). So by taking antibiotics you could end up giving yourself a bacterial infection.

di11on

Thanks for the reply.

So green/yellow mucus is a result of white blood cells in the mucus and no necessarily a sign of bacterial infection. But _can_ it be a sign of bacterial infection? If not, why do GPs ask you the colour? I have had many GPs ask me this question - in Ireland and in France.

challengemaster

Like anything - it's part of forming a diagnosis. They need to know what's wrong so they can treat it as best as is possible. No doctor would rely solely on the colour of nasal mucus (snot) to determine the underlying cause of an infection, but the colour and consistency may be indicative that an infection is present, or point towards other symptoms the patient may be unaware of.

The colour of sputum however, is associated with bacterial infections